Which diff oils do u recommend

[ZXTOM]

I use Redline oil.

 

IMO, the best you can get

[SAKO79]

Anyone use swepco synthetic gear oil

[fondupot]

What are the differential capacities? Amsoil lists 3 pints for the front diff (8.25 ring gear) and 4.1 pints for the rear (8.6 ring gear). Is this correct?

 

The owners manual does not list capacities, only the type of fluid. It says 80W90 for the front, and 75w85 for the rear. But I suspect 75W90 will be perfectly fine in both the front and rear.

[LongrangeLauber]

Go to the Amsoil website, they list the capacities for every fluid in the truck

[BuyAmericanIron]

After much research and studying specs, I would go with Amsoil in the differentials. While you are under there, I always recommend changing the transfer case oil at the same time. It only takes about 1.5 quarts of Dexron VI. If you plan to trade your truck in two or three years, don't waste your time and money, just drive it.

[fondupot]

Go to the Amsoil website, they list the capacities for every fluid in the truck

 

Yea I know. I listed the capacities Amsoil says, but are their capacities correct? I cant find the GM specification for capacities anywhere.

[LongrangeLauber]

I believe they just copy GM specs

[Black02Silverado]

 

Yea I know. I listed the capacities Amsoil says, but are their capacities correct? I cant find the GM specification for capacities anywhere.

Yes the capacities listed on the AMSOIL page are correct.

[redwngr]

What are the differential capacities? Amsoil lists 3 pints for the front diff (8.25 ring gear) and 4.1 pints for the rear (8.6 ring gear). Is this correct?

 

The owners manual does not list capacities, only the type of fluid. It says 80W90 for the front, and 75w85 for the rear. But I suspect 75W90 will be perfectly fine in both the front and rear.

The 2016 manual says front 75W90

and 1500 series rear diff is 75W85.

 

Somewhere I read that GM developed a new rear diff fluid for this generation truck and considers it to be 'lubed for life'.

 

(Which is why there is no change interval for diff's in the maintenance schedule, and probably why there is no volume listed in the manual either.)

 

Transfer case still needs to be changed. (1.6 qt of Dex VI)

Transmission still needs to be changed. If it is an 8 speed, it also has a new fluid - Dex HP

[Willshire]

Locking rear ends don't have clutches so no friction modifier needed. My 9.3" in my 64 pontiac has clutches so it gets gm fric mod. If it is a limited slip it needs anti slip additive for conditioning the clutches. But GM doesn't put LSD's in their rears so never a need for additive unless you went aftermarket LSD

[07Softail]

Locking rear ends don't have clutches so no friction modifier needed. My 9.3" in my 64 pontiac has clutches so it gets gm fric mod. If it is a limited slip it needs anti slip additive for conditioning the clutches. But GM doesn't put LSD's in their rears so never a need for additive unless you went aftermarket LSD

G80's have fiction disc.

 

RT

[redwngr]

G80 should NEVER have limited slip additive put into it.

[07Softail]

G80 should NEVER have limited slip additive put into it.

G80's should never go into a GM product!

 

RT

[Willshire]

G80's should never go into a GM product!

 

RT

Lol. Is that to say the g80 doesn't belong in anything? Lol

 

If 90% of people use the locker under slipping conditions, the g80 is a fine unit and works very well. If you intend to punish the rear end doing dry pavement brake stands, you will eventually break it. I was hard on my 08 Sierra and after 240k miles it still worked mint. Easier to sell a g80 to 90% than a trutrac. Eaton has built rears for gm since the 70's. That partnership isn't going anywhere

[SAKO79]

Well I ended up going with royal purple 75-90 in the front and rear diff